2. With an electric mixer, beat the egg whites and salt on high speed until soft peaks form.
3. Continue mixing on high speed while adding 1/2 cup of the sugar. Add the remaining sugar by the tablespoon. Beat for another 1-2 minutes, until the mixture is stiff and shiny. Gently fold in the cocoa powder until just combined.
4. Drop by the spoonful onto the cookie sheets. Flatten each cookie slightly with the back of a spoon.
5. Bake until meringues are firm and lightly browned, about 30 minutes. Let cool.